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- /*
- This file is part of GNUnet.
- Copyright (C) 2001-2012 GNUnet e.V.
- GNUnet is free software: you can redistribute it and/or modify it
- under the terms of the GNU Affero General Public License as published
- by the Free Software Foundation, either version 3 of the License,
- or (at your option) any later version.
- GNUnet is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Affero General Public License for more details.
- You should have received a copy of the GNU Affero General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- SPDX-License-Identifier: AGPL3.0-or-later
- */
- /**
- * @author Christian Grothoff
- *
- * @file
- * Disk IO APIs
- *
- * @defgroup disk Disk library
- * Disk IO APIs
- * @{
- */
- #ifndef GNUNET_DISK_LIB_H
- #define GNUNET_DISK_LIB_H
- /**
- * Handle used to manage a pipe.
- */
- struct GNUNET_DISK_PipeHandle;
- /**
- * Type of a handle.
- */
- enum GNUNET_FILE_Type
- {
- /**
- * Handle represents an event.
- */
- GNUNET_DISK_HANLDE_TYPE_EVENT,
- /**
- * Handle represents a file.
- */
- GNUNET_DISK_HANLDE_TYPE_FILE,
- /**
- * Handle represents a pipe.
- */
- GNUNET_DISK_HANLDE_TYPE_PIPE
- };
- /**
- * Handle used to access files (and pipes).
- */
- struct GNUNET_DISK_FileHandle
- {
- /**
- * File handle on Unix-like systems.
- */
- int fd;
- };
- /* we need size_t, and since it can be both unsigned int
- or unsigned long long, this IS platform dependent;
- but "stdlib.h" should be portable 'enough' to be
- unconditionally available... */
- #include <stdlib.h>
- #include "gnunet_configuration_lib.h"
- #include "gnunet_scheduler_lib.h"
- #ifdef __cplusplus
- extern "C"
- {
- #if 0 /* keep Emacsens' auto-indent happy */
- }
- #endif
- #endif
- /**
- * Specifies how a file should be opened.
- */
- enum GNUNET_DISK_OpenFlags
- {
- /**
- * Open the file for reading
- */
- GNUNET_DISK_OPEN_READ = 1,
- /**
- * Open the file for writing
- */
- GNUNET_DISK_OPEN_WRITE = 2,
- /**
- * Open the file for both reading and writing
- */
- GNUNET_DISK_OPEN_READWRITE = 3,
- /**
- * Fail if file already exists
- */
- GNUNET_DISK_OPEN_FAILIFEXISTS = 4,
- /**
- * Truncate file if it exists
- */
- GNUNET_DISK_OPEN_TRUNCATE = 8,
- /**
- * Create file if it doesn't exist
- */
- GNUNET_DISK_OPEN_CREATE = 16,
- /**
- * Append to the file
- */
- GNUNET_DISK_OPEN_APPEND = 32
- };
- /**
- * Specifies what type of memory map is desired.
- */
- enum GNUNET_DISK_MapType
- {
- /**
- * Read-only memory map.
- */
- GNUNET_DISK_MAP_TYPE_READ = 1,
- /**
- * Write-able memory map.
- */
- GNUNET_DISK_MAP_TYPE_WRITE = 2,
- /**
- * Read-write memory map.
- */
- GNUNET_DISK_MAP_TYPE_READWRITE = 3
- };
- /**
- * File access permissions, UNIX-style.
- */
- enum GNUNET_DISK_AccessPermissions
- {
- /**
- * Nobody is allowed to do anything to the file.
- */
- GNUNET_DISK_PERM_NONE = 0,
- /**
- * Owner can read.
- */
- GNUNET_DISK_PERM_USER_READ = 1,
- /**
- * Owner can write.
- */
- GNUNET_DISK_PERM_USER_WRITE = 2,
- /**
- * Owner can execute.
- */
- GNUNET_DISK_PERM_USER_EXEC = 4,
- /**
- * Group can read.
- */
- GNUNET_DISK_PERM_GROUP_READ = 8,
- /**
- * Group can write.
- */
- GNUNET_DISK_PERM_GROUP_WRITE = 16,
- /**
- * Group can execute.
- */
- GNUNET_DISK_PERM_GROUP_EXEC = 32,
- /**
- * Everybody can read.
- */
- GNUNET_DISK_PERM_OTHER_READ = 64,
- /**
- * Everybody can write.
- */
- GNUNET_DISK_PERM_OTHER_WRITE = 128,
- /**
- * Everybody can execute.
- */
- GNUNET_DISK_PERM_OTHER_EXEC = 256
- };
- /**
- * Constants for specifying how to seek. Do not change values or order,
- * some of the code depends on the specific numeric values!
- */
- enum GNUNET_DISK_Seek
- {
- /**
- * Seek an absolute position (from the start of the file).
- */
- GNUNET_DISK_SEEK_SET = 0,
- /**
- * Seek a relative position (from the current offset).
- */
- GNUNET_DISK_SEEK_CUR = 1,
- /**
- * Seek an absolute position from the end of the file.
- */
- GNUNET_DISK_SEEK_END = 2
- };
- /**
- * Enumeration identifying the two ends of a pipe.
- */
- enum GNUNET_DISK_PipeEnd
- {
- /**
- * The reading-end of a pipe.
- */
- GNUNET_DISK_PIPE_END_READ = 0,
- /**
- * The writing-end of a pipe.
- */
- GNUNET_DISK_PIPE_END_WRITE = 1
- };
- /**
- * Checks whether a handle is invalid
- *
- * @param h handle to check
- * @return #GNUNET_YES if invalid, #GNUNET_NO if valid
- */
- int
- GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
- /**
- * Check that fil corresponds to a filename
- * (of a file that exists and that is not a directory).
- *
- * @param fil filename to check
- * @return #GNUNET_YES if yes, #GNUNET_NO if not a file, #GNUNET_SYSERR if something
- * else (will print an error message in that case, too).
- */
- int
- GNUNET_DISK_file_test (const char *fil);
- /**
- * Move a file out of the way (create a backup) by
- * renaming it to "orig.NUM~" where NUM is the smallest
- * number that is not used yet.
- *
- * @param fil name of the file to back up
- */
- void
- GNUNET_DISK_file_backup (const char *fil);
- /**
- * Move the read/write pointer in a file
- * @param h handle of an open file
- * @param offset position to move to
- * @param whence specification to which position the offset parameter relates to
- * @return the new position on success, GNUNET_SYSERR otherwise
- */
- off_t
- GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, off_t offset,
- enum GNUNET_DISK_Seek whence);
- /**
- * Get the size of the file (or directory) of the given file (in
- * bytes).
- *
- * @param filename name of the file or directory
- * @param size set to the size of the file (or,
- * in the case of directories, the sum
- * of all sizes of files in the directory)
- * @param include_symbolic_links should symbolic links be
- * included?
- * @param single_file_mode #GNUNET_YES to only get size of one file
- * and return #GNUNET_SYSERR for directories.
- * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
- */
- int
- GNUNET_DISK_file_size (const char *filename,
- uint64_t *size,
- int include_symbolic_links,
- int single_file_mode);
- /**
- * Obtain some unique identifiers for the given file
- * that can be used to identify it in the local system.
- * This function is used between GNUnet processes to
- * quickly check if two files with the same absolute path
- * are actually identical. The two processes represent
- * the same peer but may communicate over the network
- * (and the file may be on an NFS volume). This function
- * may not be supported on all operating systems.
- *
- * @param filename name of the file
- * @param dev set to the device ID
- * @param ino set to the inode ID
- * @return #GNUNET_OK on success
- */
- int
- GNUNET_DISK_file_get_identifiers (const char *filename,
- uint64_t *dev,
- uint64_t *ino);
- /**
- * Create an (empty) temporary file on disk. If the given name is not
- * an absolute path, the current 'TMPDIR' will be prepended. In any case,
- * 6 random characters will be appended to the name to create a unique
- * filename.
- *
- * @param t component to use for the name;
- * does NOT contain "XXXXXX" or "/tmp/".
- * @return NULL on error, otherwise name of fresh
- * file on disk in directory for temporary files
- */
- char *
- GNUNET_DISK_mktemp (const char *t);
- /**
- * Create an (empty) temporary directory on disk. If the given name is not an
- * absolute path, the current 'TMPDIR' will be prepended. In any case, 6
- * random characters will be appended to the name to create a unique name.
- *
- * @param t component to use for the name;
- * does NOT contain "XXXXXX" or "/tmp/".
- * @return NULL on error, otherwise name of freshly created directory
- */
- char *
- GNUNET_DISK_mkdtemp (const char *t);
- /**
- * Open a file. Note that the access permissions will only be
- * used if a new file is created and if the underlying operating
- * system supports the given permissions.
- *
- * @param fn file name to be opened
- * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
- * @param perm permissions for the newly created file, use
- * #GNUNET_DISK_PERM_NONE if a file could not be created by this
- * call (because of flags)
- * @return IO handle on success, NULL on error
- */
- struct GNUNET_DISK_FileHandle *
- GNUNET_DISK_file_open (const char *fn,
- enum GNUNET_DISK_OpenFlags flags,
- enum GNUNET_DISK_AccessPermissions perm);
- /**
- * Get the size of an open file.
- *
- * @param fh open file handle
- * @param size where to write size of the file
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
- */
- int
- GNUNET_DISK_file_handle_size (struct GNUNET_DISK_FileHandle *fh,
- off_t *size);
- /**
- * Creates an interprocess channel
- *
- * @param blocking_read creates an asynchronous pipe for reading if set to #GNUNET_NO
- * @param blocking_write creates an asynchronous pipe for writing if set to #GNUNET_NO
- * @param inherit_read 1 to make read handle inheritable, 0 otherwise (NT only)
- * @param inherit_write 1 to make write handle inheritable, 0 otherwise (NT only)
- * @return handle to the new pipe, NULL on error
- */
- struct GNUNET_DISK_PipeHandle *
- GNUNET_DISK_pipe (int blocking_read,
- int blocking_write,
- int inherit_read,
- int inherit_write);
- /**
- * Creates a pipe object from a couple of file descriptors.
- * Useful for wrapping existing pipe FDs.
- *
- * @param blocking_read creates an asynchronous pipe for reading if set to #GNUNET_NO
- * @param blocking_write creates an asynchronous pipe for writing if set to #GNUNET_NO
- * @param fd an array of two fd values. One of them may be -1 for read-only or write-only pipes
- *
- * @return handle to the new pipe, NULL on error
- */
- struct GNUNET_DISK_PipeHandle *
- GNUNET_DISK_pipe_from_fd (int blocking_read,
- int blocking_write,
- int fd[2]);
- /**
- * Closes an interprocess channel
- * @param p pipe
- * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
- */
- int
- GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
- /**
- * Closes one half of an interprocess channel
- *
- * @param p pipe to close end of
- * @param end which end of the pipe to close
- * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
- */
- int
- GNUNET_DISK_pipe_close_end (struct GNUNET_DISK_PipeHandle *p,
- enum GNUNET_DISK_PipeEnd end);
- /**
- * Detaches one of the ends from the pipe.
- * Detached end is a fully-functional FileHandle, it will
- * not be affected by anything you do with the pipe afterwards.
- * Each end of a pipe can only be detched from it once (i.e.
- * it is not duplicated).
- *
- * @param p pipe to detach an end from
- * @param end which end of the pipe to detach
- * @return Detached end on success, NULL on failure
- * (or if that end is not present or is closed).
- */
- struct GNUNET_DISK_FileHandle *
- GNUNET_DISK_pipe_detach_end (struct GNUNET_DISK_PipeHandle *p,
- enum GNUNET_DISK_PipeEnd end);
- /**
- * Close an open file.
- *
- * @param h file handle
- * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
- */
- int
- GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
- /**
- * Get the handle to a particular pipe end
- *
- * @param p pipe
- * @param n end to access
- * @return handle for the respective end
- */
- const struct GNUNET_DISK_FileHandle *
- GNUNET_DISK_pipe_handle (const struct GNUNET_DISK_PipeHandle *p,
- enum GNUNET_DISK_PipeEnd n);
- /**
- * Update POSIX permissions mask of a file on disk. If both argumets
- * are #GNUNET_NO, the file is made world-read-write-executable (777).
- * Does nothing on W32.
- *
- * @param fn name of the file to update
- * @param require_uid_match #GNUNET_YES means 700
- * @param require_gid_match #GNUNET_YES means 770 unless @a require_uid_match is set
- */
- void
- GNUNET_DISK_fix_permissions (const char *fn,
- int require_uid_match,
- int require_gid_match);
- /**
- * Get a handle from a native integer FD.
- *
- * @param fno native integer file descriptor
- * @return file handle corresponding to the descriptor
- */
- struct GNUNET_DISK_FileHandle *
- GNUNET_DISK_get_handle_from_int_fd (int fno);
- /**
- * Get a handle from a native FD.
- *
- * @param fd native file descriptor
- * @return file handle corresponding to the descriptor
- */
- struct GNUNET_DISK_FileHandle *
- GNUNET_DISK_get_handle_from_native (FILE *fd);
- /**
- * Read the contents of a binary file into a buffer.
- *
- * @param h handle to an open file
- * @param result the buffer to write the result to
- * @param len the maximum number of bytes to read
- * @return the number of bytes read on success, #GNUNET_SYSERR on failure
- */
- ssize_t
- GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h,
- void *result,
- size_t len);
- /**
- * Read the contents of a binary file into a buffer.
- * Guarantees not to block (returns GNUNET_SYSERR and sets errno to EAGAIN
- * when no data can be read).
- *
- * @param h handle to an open file
- * @param result the buffer to write the result to
- * @param len the maximum number of bytes to read
- * @return the number of bytes read on success, #GNUNET_SYSERR on failure
- */
- ssize_t
- GNUNET_DISK_file_read_non_blocking (const struct GNUNET_DISK_FileHandle *h,
- void *result,
- size_t len);
- /**
- * Read the contents of a binary file into a buffer.
- *
- * @param fn file name
- * @param result the buffer to write the result to
- * @param len the maximum number of bytes to read
- * @return number of bytes read, #GNUNET_SYSERR on failure
- */
- ssize_t
- GNUNET_DISK_fn_read (const char *fn,
- void *result,
- size_t len);
- /**
- * Write a buffer to a file.
- *
- * @param h handle to open file
- * @param buffer the data to write
- * @param n number of bytes to write
- * @return number of bytes written on success, #GNUNET_SYSERR on error
- */
- ssize_t
- GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
- const void *buffer,
- size_t n);
- /**
- * Write a buffer to a file, blocking, if necessary.
- *
- * @param h handle to open file
- * @param buffer the data to write
- * @param n number of bytes to write
- * @return number of bytes written on success, #GNUNET_SYSERR on error
- */
- ssize_t
- GNUNET_DISK_file_write_blocking (const struct GNUNET_DISK_FileHandle *h,
- const void *buffer,
- size_t n);
- /**
- * Write a buffer to a file. If the file is longer than
- * the given buffer size, it will be truncated.
- *
- * @param fn file name
- * @param buffer the data to write
- * @param n number of bytes to write
- * @param mode file permissions
- * @return number of bytes written on success, #GNUNET_SYSERR on error
- */
- ssize_t
- GNUNET_DISK_fn_write (const char *fn,
- const void *buffer,
- size_t n,
- enum GNUNET_DISK_AccessPermissions mode);
- /**
- * Copy a file.
- *
- * @param src file to copy
- * @param dst destination file name
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
- */
- int
- GNUNET_DISK_file_copy (const char *src,
- const char *dst);
- /**
- * Scan a directory for files.
- *
- * @param dir_name the name of the directory
- * @param callback the method to call for each file
- * @param callback_cls closure for @a callback
- * @return the number of files found, -1 on error
- */
- int
- GNUNET_DISK_directory_scan (const char *dir_name,
- GNUNET_FileNameCallback callback,
- void *callback_cls);
- /**
- * Create the directory structure for storing
- * a file.
- *
- * @param filename name of a file in the directory
- * @returns #GNUNET_OK on success, #GNUNET_SYSERR on failure,
- * #GNUNET_NO if directory exists but is not writeable
- */
- int
- GNUNET_DISK_directory_create_for_file (const char *filename);
- /**
- * Test if @a fil is a directory and listable. Optionally, also check if the
- * directory is readable. Will not print an error message if the directory does
- * not exist. Will log errors if #GNUNET_SYSERR is returned (i.e., a file exists
- * with the same name).
- *
- * @param fil filename to test
- * @param is_readable #GNUNET_YES to additionally check if @a fil is readable;
- * #GNUNET_NO to disable this check
- * @return #GNUNET_YES if yes, #GNUNET_NO if not; #GNUNET_SYSERR if it
- * does not exist or `stat`ed
- */
- int
- GNUNET_DISK_directory_test (const char *fil, int is_readable);
- /**
- * Remove all files in a directory (rm -rf). Call with
- * caution.
- *
- * @param filename the file to remove
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
- */
- int
- GNUNET_DISK_directory_remove (const char *filename);
- /**
- * Remove the directory given under @a option in
- * section [PATHS] in configuration under @a cfg_filename
- *
- * @param cfg_filename configuration file to parse
- * @param option option with the dir name to purge
- */
- void
- GNUNET_DISK_purge_cfg_dir (const char *cfg_filename,
- const char *option);
- /**
- * Implementation of "mkdir -p"
- *
- * @param dir the directory to create
- * @returns #GNUNET_SYSERR on failure, #GNUNET_OK otherwise
- */
- int
- GNUNET_DISK_directory_create (const char *dir);
- /**
- * Lock a part of a file.
- *
- * @param fh file handle
- * @param lock_start absolute position from where to lock
- * @param lock_end absolute position until where to lock
- * @param excl #GNUNET_YES for an exclusive lock
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
- */
- int
- GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh,
- off_t lock_start,
- off_t lock_end, int excl);
- /**
- * Unlock a part of a file.
- *
- * @param fh file handle
- * @param unlock_start absolute position from where to unlock
- * @param unlock_end absolute position until where to unlock
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
- */
- int
- GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh,
- off_t unlock_start,
- off_t unlock_end);
- /**
- * @brief Removes special characters as ':' from a filename.
- * @param fn the filename to canonicalize
- */
- void
- GNUNET_DISK_filename_canonicalize (char *fn);
- /**
- * @brief Change owner of a file
- * @param filename file to change
- * @param user new owner of the file
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
- */
- int
- GNUNET_DISK_file_change_owner (const char *filename,
- const char *user);
- /**
- * Opaque handle for a memory-mapping operation.
- */
- struct GNUNET_DISK_MapHandle;
- /**
- * Map a file into memory
- * @param h open file handle
- * @param m handle to the new mapping (will be set)
- * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
- * @param len size of the mapping
- * @return pointer to the mapped memory region, NULL on failure
- */
- void *
- GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
- struct GNUNET_DISK_MapHandle **m,
- enum GNUNET_DISK_MapType access,
- size_t len);
- /**
- * Unmap a file
- *
- * @param h mapping handle
- * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
- */
- int
- GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
- /**
- * Write file changes to disk
- *
- * @param h handle to an open file
- * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
- */
- int
- GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
- #if 0 /* keep Emacsens' auto-indent happy */
- {
- #endif
- #ifdef __cplusplus
- }
- #endif
- /* ifndef GNUNET_DISK_LIB_H */
- #endif
- /** @} */ /* end of group */
- /* end of gnunet_disk_lib.h */
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